java - 如何为 BigDecimal 编写 Junit 测试用例

Question

您好，我尝试构建一个简单的银行应用程序，现在我想编写提款存款和转账的测试用例，请帮助我，这是代码

帐户.java

public BigInteger getAccountNumber() {
        return accountNumber;
    }
    public void setAccountNumber(BigInteger accountNumber) {
        this.accountNumber = accountNumber;
    }
    public String getType() {
        return type;
    }
    public void setType(String type) {
        this.type = type;
    }
    public String getOwner() {
        return ownerName;
    }
    public void setOwner(String owner) {
        this.ownerName = owner;
    }
    public BigDecimal getBalance() {
        return balance;
    }
    public BigDecimal setBalance(BigDecimal balance) {
        this.balance = balance;
        return balance;
    }

银行.java

package org.mybank.entities;
// Bank details. 
public class Bank {
    private String IFSC;
    private Integer id;
    private String address;
    public String getIFSC() {
        return IFSC;
    }
    public void setIFSC(String iFSC) {
        IFSC = iFSC;
    }
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getAddress() {
        return address;
    }
    public void setAddress(String address) {
        this.address = address;
    }




}

chekings.java

package org.mybank.entities;
// checking account extending Account
public class Chekings extends Account {
    private String checkingtype;

    public String getCheckingtype() {
        return checkingtype;
    }

    public void setCheckingtype(String checkingtype) {
        this.checkingtype = checkingtype;
    }


}

节省

package org.mybank.entities;
// Savings account extending Account
public class Savings extends Account {

    private String savingsType;

    public String getSavingsType() {
        return savingsType;
    }

    public void setSavingsType(String savingsType) {
        this.savingsType = savingsType;
    }



}

交易.java

package org.mybank.entities;

import java.math.BigDecimal;
import java.math.BigInteger;

public class Transaction {
 // main class
    private BigDecimal amout;
    private String transactionType;
    private BigInteger sourceAccNum;
    private BigInteger destAccNum;
    private Integer transactionId;  

}

Operations.java 这是 iam 执行提款、存款和转账测试用例的地方

package org.mybank.business;

import java.math.BigDecimal;
import java.math.BigInteger;

import org.mybank.entities.Account;
import org.mybank.entities.Savings;

public class Operations {
    // withdraw specified amount from the specified account number
    public void withdrawl(BigInteger accNum, BigDecimal amount) throws Exception {
        Account acc = findAccount(accNum);
        if (acc!=null) { // check if it is valid account
            if (acc.getBalance().floatValue() >= amount.floatValue()) {
                if (acc.getType().equals("SAVINGS")) { // if savings account. 
                    Savings savingsAccount = getSavingsAccount(acc.getAccountNumber());
                    if (savingsAccount.getSavingsType().equals("INDIVIDUAL") && amount.floatValue() > 1000) {
                        throw new Exception("Idividual account cannot withdraw amount more than 1000.");
                    } else {

                        // create a transaction here
                        acc.setBalance(new BigDecimal(acc.getBalance().floatValue() - amount.floatValue()));
                    }
                }
            } else {
                throw new Exception("Insufficient funds");
            } 
        }else{
            throw new Exception("Invalid Account");
        }

    }

    //returns saving acc based on account number
    private Savings getSavingsAccount(BigInteger accountNumber) {
        return new Savings();

    }

    // returns account based on account number
    private Account findAccount(BigInteger accNum) {
        // TODO Auto-generated method stub

        return new Account();
    }

    // transfers funds from source to destination. 
    public void transfer(BigInteger sourceAccNum, BigInteger destAccNum, BigDecimal amount) throws Exception {
        Account src = findAccount(sourceAccNum);
        Account dest = findAccount(destAccNum);
        if(src!=null && dest!=null){
            if(src.getBalance().floatValue()>amount.floatValue()){
                // create a new trascation instance here
                src.setBalance(new BigDecimal(src.getBalance().floatValue() - amount.floatValue()));
                dest.setBalance(new BigDecimal(dest.getBalance().floatValue() + amount.floatValue()));
            }else{
                throw new Exception("Insufficient funds");
            }
        }else{
            throw new Exception("Invalid account.");
        }
    }
    // deposit amount in specified account. 
    public BigDecimal deposit(BigInteger accNum, BigDecimal amount) throws Exception {
        Account acc = findAccount(accNum);
        if(acc!=null){
            // create a new trascation instance here
            acc.setBalance(new BigDecimal(acc.getBalance().floatValue() + amount.floatValue()));
        }else{
            throw new Exception("Invalid Account");
        }
        return amount;
    }
}

这是我编写的测试代码。它总是失败。如果我使用 try catch block ，它总是通过测试帮助我编写完美的测试代码。这是我第一次在Junit中编写测试代码。

import static org.junit.Assert.*;

import java.math.BigDecimal;
import java.math.BigInteger;

import org.junit.Test;
import org.mybank.business.Operations;

import junit.framework.Assert;

public class banking {

    @Test
    public void deposittest() throws Exception  {
        Operations optest = new Operations();
        int a= 123;
        Double b= (double) 2000;
         BigDecimal result;

            result = optest.deposit(BigInteger.valueOf(a),BigDecimal.valueOf(b));
            assertEquals(2000,result);
        } 

    }

Answer 1

deposit 方法不是设置余额，而是添加到现有余额。所以账户里最好已经有余额了。至少，您可以在 balance 字段的声明中使用初始值设定项:

class Account {
    ...
    private BigDecimal balance = BigDecimal.valueOf(0);
    ...
}

您还可以将初始化作为构造函数的一部分进行处理。